Saturday, August 02, 2008

Brain signal decoder

Interfacing with the brain to control devices such as wheelchairs, robots and prosthetic devices has great potential. Monkeys have shown impressive ability to control robot limbs using brain implants, but must "rewire" their brains through training to do it.

It would make things easier to use the signals naturally used for hand-eye coordination. But nobody has been able to figure out how the part of the brain responsible for hand-eye coordination, the primary motor cortex, does its job. Even recording the activity of this brain region has proved difficult.

Now, John Donoghue and colleagues at Brown University in Providence, Rhode Island, have designed a new implant to make the task easier. They have also created software that turns these brain signals into code that controls an external device.

The team tested the device on the brains of monkeys as they watched objects move in front of them. In this way, the researchers built up a database of signals that could be used to work out a decoding strategy.

The result is a brain implant that can translate the hand trajectory signals produced by the brain and use them to control an external device.

Thursday, October 04, 2007

Brain radiator

In severe epileptic fits, over-excited brain cells fire at such a rate they can raise the brain's temperature in that area. This causes more nerves to fire in a feedback mechanism that makes the fit even worse. One way of preventing such escalating fits is to cool the area of the brain that is susceptible.

So Takashi Saito and colleagues at Yamaguchi University in Japan have developed a heat pipe that is surgically implanted into the affected region of the brain and then connected to a heat sink on the outside of the skull. This device carries heat away from the affected area, keeping it cool and reducing the chances of severe epileptic fits in future.

Monday, March 26, 2007

Brain decoder

One of the great challenges for neuroscientists is to understand the code the brain uses to send information along neurons. Researchers at Brown University on Rhode Island have now come up with a device that may help to tackle the mystery.

The machine works by measuring the signals produced by primary motor cortex – the part of the brain responsible for hand-eye co-ordination. A computer then attempts to reproduce this signal, which is used to stimulate the movement in a primate limb.

By minimising the difference between the original signal and the artificial one and by comparing the difference in the effects these two signals have on limb movement, the researchers hope to decrypt the neuronal code used by the brain to control muscle movement. The researchers say same signal-processing techniques could eventually be used to control artificial limbs, wheelchairs and even speech synthesisers.